Large items (coffee pots, toasters, etc.) should be put into a cupboard or placed on the bed (some folks wrap them in towels, the put them on the bed).
Small decorative items could be attached with museum putty. It does work great, but the item will be in one place (so moving it to dust, etc.).
If you get into the habit of putting things away right after use or after the last use of the stop, then it makes getting ready to "break camp" a lot easier and quicker.
How long it takes to get used to really depends on you. Some people adjust very quickly, others take some time. The important thing is to take it slow and don't pressure yourself. If you feel yourself getting stressed, then pull over and stop for a while. Driving stressed will create far more problems than anything else.